COMMUTER LTT UNAUTHORIZED TAXI UNAUTHORIZED RWY XING AFTER LNDG AT JFK.

Narrative

THE EVENT WAS FLT LANDED ON RWY 22L AT JFK; AND RECEIVED TAXI INSTRUCTIONS FROM THE TWR TO TURN R ON J AND HOLD SHORT OF 22R. DUE TO THE TAXIWAY INTXN THE CAPT; WHICH WAS IN CTL OF THE ACFT; CONFUSED RWY 31L WITH J AND CROSSED THE HOLD LINE FOR 31L. DURING THIS; MYSELF (THE FO) WAS LOOKING DOWN CHKING THE ARPT DIAGRAM; NOT KNOWING WHERE THE CAPT WAS GOING. WHEN I LOOKED UP WE IMMEDIATELY REALIZED THE MISTAKE AND CLRED THE RWY. WE THEN RECEIVED NEW TAXI INSTRUCTIONS FROM TWR TO CROSS 31L AND TURN L ON J CROSS 22R AND MONITOR GND AND TAXI TO THE GATE. AFTER ALL OF THE CONFUSION WE BELIEVE THAT WE WERE SUPPOSED TO CONTACT GND INSTEAD OF JUST MONITORING THE FREQ AFTER WE WERE CLRED OF 22R. WE DID REALIZE THIS AND WE WERE ABLE TO CALL THEM. THE REASON FOR THIS WAS THE FREQ WAS A LITTLE CONGESTED. THIS ENTIRE SITUATION WAS DISCUSSED OVER THE TELEPHONE AND THE CTLR SAID THAT THERE WAS NO OTHER TFC THAT WAS INVOLVED AND THERE WAS NO CONFLICT OR ANY PROBLEM. SUPPLEMENTAL INFO FROM ACN 199063: TWR CAUGHT ME AT THE SAME TIME I REALIZED IT AND TURNED L ON J. I SHOULD HAVE STOPPED AND MADE SURE. AND I SHOULDN'T HAVE MISSED THE RED/GREEN STOP BAR.